Page 4 - PPE GUIDELINE
P. 4
Guidelines on the Use of PPE Against Chemical Hazards
Negative pressure respirator
A respirator in which the air pressure inside the respirator inlet covering is less than
the ambient air pressure during inhalation.
Oxygen-deficient atmosphere
An atmosphere, which does not contain enough oxygen to fully support the body’s
metabolic processes. It is generally acknowledged that an atmosphere with oxygen
concentration below 19.5% by volume is deficient in oxygen.
Positive pressure respirator
A respirator in which the pressure inside the respirator inlet covering is higher than
the ambient air pressure.
Respirator
A personal device designed to protect the user from the inhalation of hazardous
atmosphere.
Respirator inlet covering
The portion of a respirator that connects the user’s respiratory tract to an air-purifying
device or a respirable gas source, or both. It may be a face-piece, helmet or hood. The
inlet covering serves as a barrier against the contaminated atmosphere and as a
framework to which air-purifying elements may be attached.
Service life
The amount of time required to reach breakthrough for a cartridge or a canister.
Sorbent
A material that is contained in a canister or cartridge that can remove specific gases or
vapours from the inhaled air.
Vapour
The gaseous phase of matter that normally exists in a liquid or solid state at room
temperature
Department of Occupational Safety & Health, Ministry of Human Resources, Malaysia October 2005 4
